Saturday, June 19, 2010

Maharashtra - - Geographically Speaking

The word Maharashtra, the land of the Marathi speaking people, appears to be derived from Maharashtri, an old form of Prakrit. Some believe that the word indicates that it was the land of the Mahars and the Rattas, while others consider it to be a corruption of the term 'Maha Kantara' (the Great Forest), a synonym for 'Dandakaranya'.

Located in the north centre of Peninsular India, with a command of the Arabian Sea through its port of Mumbai, Maharashtra has a remarkable physical homogeneity, enforced by its underlying geology. The dominant physical trait of the state is its plateau character. The Maharashtra Desh is a plateau of plateaux, its western upturned rims rising to form the Sahyadri Range and its slopes gently descending towards the east and southeast. The major rivers and their master tributaries have carved the plateaux into alternating broad-river valleys and intervening higher lever interfluves, such as the Ahmednagar, Buldana, and Yavatmal plateaux.

The Sahyadri Range is the physical backbone of Maharashtra. Rising on an average to an elevation of 1000m. it falls in steep cliffs, to the Konkan on the west. Eastwards, the hill country falls in steps through a transitional area known as Mawal to the plateau level. The series of crowning plateaux on the crest forms a distinctive feature of the Sahyadri Range.

The Konkan, lying between the Arabian Sea and the Sahyadri Range is narrow coastal lowland, barely 50 km. wide. Though mostly below 200 m., it is far from being a plain country. Highly dissected and broken, the Konkan alternates between narrow, steep-sided valleys and low laterite plateaux.

The Satpudas, hills along the northern border, and the Bhamragad-Chiroli-Gaikhuri Ranges on the eastern border form physical barriers preventing easy movement, but also serve as natural limits to the state.

Except around Mumbai, and along the eastern limits, the State of Maharashtra presents a monotonously uniform, flat-topped skyline. This topography of the state is the outcome of its geological structure. The state area, barring the extreme eastern Vidarbha region, parts of Kolhapur and Sindhudurg, is practically co-terminous with the Deccan Traps. Roughly 60 to 90 million years ago, the outpouring of basic lava through fissures formed horizontally bedded basalt over large areas. Variations in their composition and structure have resulted in massive, well-jointed steel-grey cliff faces alternating with structural benches of vesicular amygdaloid lava and ash layers, all of which contribute to the pyramida-shaped hills and crest-level plateaux or mesas. Earth sculpturing under the tropical climate completed the panorama-sharply defining the landform features in the semi-arid conditions, and rounding the hilltops under wetter condition. Fluvial action by the Krishna, Bhima, Godavari, Tapi-Purna and Wardha-Wainganga river systems has further aided in the compartmentalisation of the Desh into broad, open river valleys, alternating with plateau interfluves, that form the ribs of the Sahyadrian backbone. In sharp contrast, the hill torrents of the Konkan, barely a 100 km. long, tumble down as roaring streams which flow in deeply entrenched valleys to terminate in tidal estuaries.

The state enjoys a tropical monsoon climate; the hot scorching summer from March onwards yields to the rainy monsoon in early June. The rich green cover of the monsoon season persists during the mild winter that follows through an unpleasant October transition, but turns into a dusty, barren brown as the summer sets in again. The seasonal rains from the western sea-clouds are very heavy and the rainfall is over 400 cm., on the Sahyadrian crests. The Konkan on the windward side is also endowed with heavy rainfall, declining northwards. East of the Sahyadri, the rainfall diminishes to a meagre 70 cm. in the western plateau districts, with Solapur-Ahmednagar lying in the heart of the dry zone. The rains increase slightly, later in the season, eastwards in the Marathwada and Vidarbha regions.

The highly pulsatory character of the monsoon, with its short spells of rainy weather and long dry breaks, floods, as well as droughts add much to the discomfort of the rural economy.

Forests comprising only 17% of the state area cover the eastern region and the Sahyadri Range, while open scrub jungle dots the plateaux. If Maharashtra represented the Maha Kantara in the historic past, today little of it is left; vast sections have been denuded and stripped of the vegetal cover.

The soils of Maharashtra are residual, derived from the underlying basalts. In the semi-dry plateau, the regur (black-cotton soil) is clayey, rich in iron, but poor in nitrogen and organic matter; it is moisture-retentive. Where redeposited along the river valleys, those kali soils are deeper and heavier, better suited for rabi crops. Farther away, with a better mixture of lime, the morand soils form the ideal Kharif zone. The higher plateau areas have pather soils, which contain more gravel. In the rainy Konkan, and the Sahyadri Range, the same basalts give rise to the brick-red laterites productive under a forest-cover, but readily stripped into a sterile varkas when the vegetation is removed. By and large, soils of Maharashtra are shallow and somewhat poor.

Water is the most precious natural resource of the state, greatly in the demand, and most unevenly distributed. A large number of villages lack drinking water, especially during the summer months, even in the wet Konkan. Barely 11% of the net sown area is irrigated. Perched water tables in the basalt aquifers have contributed to increased well irrigation, which accounts for approximately 55% of the irrigable water. The granitic-gneissic terrain in the eastern hilly area of Vidarbha accounts for all tank irrigation. Tube-wells in the Tapi-Purna alluvium and shallow wells in the coastal sands are the other main sources of water.

The mineral-bearing zones of Maharashtra lie beyond the area of the basalts in eastern Vidarbha, southern Kolhapur and the Sindhudurg area. The Chandrapur, Gadchirali, Bhandara and Nagpur Districts form the main mineral belt, with coal and manganese as the major minerals and iron ore and limestone as potential wealth. The Ratnagiri coast contains sizeable deposits of illimenite.